1. Field of the Invention
The invention relates to an optoelectronic component for conversion of electromagnetic radiation to an intensity-dependent photocurrent comprising a substrate with a microelectronic circuit, on whose surface a first layer which makes electrical contact with this and is composed of intrinsically conductive amorphous silicon a-Si:H or of its alloys is arranged, with at least one further optically active layer being arranged upstream in the light incidence direction of the first layer, and to a method for producing it.
2. Discussion of the Related Art
In the case of image sensors, which are intended to be used for recording optical radiation from the visible spectral band, matching to the spectral sensitivity of the human eye is of major importance, in order to achieve calorimetrically exact reproduction of colored image contents. This visible spectral band is between wavelengths of 380 nm and about 680 nm, with the lower boundary area being determined by the ultraviolet radiation area and the upper area being determined by the infrared radiation area. However, conventional image sensors are subject to the problem that, owing to the material characteristics of the silicon, they have significant sensitivity even beyond the visible band, in the infrared band as well. In order to avoid the image signal being corrupted by infrared components, additional measures must therefore be adopted.
On the one hand, it is known that an optical color filter system which is constructed pixel-by-pixel can be applied to the photoactive layers (U.S. Pat. No. 3,971,065).
On the other hand, it is known that additional filters can be used to suppress undesirable infrared radiation, for example interference filters or colored glass filters, which suppress light at a wavelength above about 680 nm.
Filters such as these on the one hand have the disadvantage that they represent additional design and manufacturing complexity, for example if they are installed in the optical beam path of a camera system, integrated in the lens system, and on the other hand have the disadvantage that they also absorb a not inconsiderable proportion of the light in the desired visible spectral band, and thus reduce the overall sensor sensitivity.